So it was quite an event that we were allowed to take a video camera in. One volunteer dressed as Mr Otis Peabody, owner of the land on which Hill Valley's Twin Pines Mall was later built, was sceptical. "That's a devil box you've got there", he protested, before grabbing a ticket holder for a "baptism".

Despite being in East London, there's not a lot of room for British reserve once you're inside the Secret Cinema timewarp. You will be accosted, told off for not having the correct school uniform and possibly given a police warning for jaywalking. That's before the film starts.

Of course, we wouldn't reveal everything - all you're seeing here is a glimpse. If you're lucky enough to have a ticket this summer, there's plenty of secrets left to uncover once you're there.